Distillate fuels



United States Patent 0 DlSTILLAT-E FUELS Paul Y. C. Gee, Woodbury, and Harry J. Andress, Jr., Pitman, N.'.l., assignors to Socony Mobil Oil Company, Inc., a corporation of New York No Drawing. Filed Sept. 8, 1961, Ser. No. 136,725 5 Claims. (til. 44-71) The present invention relates to improved non-lubricating petroleum fractions and, more particularly, to nonlubricating petroleum distillate s such as fuel oils containing certain additives that inhibit the oils against screen clogging and sedimentation.

It is well known that fuel oils (i.e., heater fuels, jet fuels, etc.) are prone to form sludge or sediment during periods of prolonged storage whereby burner operations are adversely affected due to clogging of screens and nozzles. Additionally, such fuel oils may contain other impurities such as rust, dirt and entrained water. The sediment and impurities tend to settle out on equipment parts (nozzles, screens, filters, etc.) to the extent of causing the equipment to fail due to clogging. Another factor, incident to the storage and handling of distillate fuels (i.e., gasoline, fuel oils) is the breathing of storage vessels which results in accumulation of considerable amounts of water in the tanks thereby presenting a problem of rusting of the tanks. Thus, when the fuel is removed for transportation, sufiicient water maybe carried along to cause rusting of ferrous metal surfaces in pipelines, tankers, and the like.

Generally speaking, in the case of fuel oils, it has been the practice to overcome the aforedescribed difiiculties with a separate additive for each purpose. The use of a plurality of additives, however, gives rise to problems of additive compatability wherebyv the choice of'additive combinations becomes restricted and, obviously, the cost of the fuel unduly increases. It is highly desirable, therefore, to employ a single additive that is effective to inhibit the fuel oil against a plurality of the aforedescribed difficulties and, particularly, against screen and nozzle clogging while also inhibiting the fuel oil against rusting of ferrous metal surfaces.

It has now been found that petroleum distillate fuels can be inhibited, by use of a single additive, against the aforestated difiiculties.

In accordance with this invention, petroleum distillate fuelsare inhibited against screen-clogging and sedimentation while also being inhibited against rusting of ferrous metals, by incorporating in said fuels certain derivatives of a methane succinamic acid as is more fully defined hereinafter.

The distillate fuels that are improved in accordance with the present invention are hydrocarbon distillate fractions having an initial boiling point of at least about 75 F. and an end boiling point no higher than about 750 F., and boiling substantially continuously throughout their distillation range. Such fuel oils are generally known as distillate fuel oils. It is to be understood, however, that this term'is not restricted to straight-run distillate fractions. The distillate fuel oils can be straight-run distillate fuels, catalytically or thermally cracked (including hydrocracked) distillate fuel oils, or mixtures of straight-run distillate fuel oils, naphthas and the like, with cracked distillate stocks. Moreover, such fuel oils can be treated in accordance with well known commercial methods, such as, acid or caustic treatment, hydrogenation, solvent refining, clay treatment, etc.

The distillate fuel oils are characterized by their relatively low viscosities, pour points, and the like. The principal property which characterizes the contemplated hydrocarbons, however, is the distillation range. As mentioned hereinbefore, this range will lie between about greases Patented June 29, 1965 75 F. and about 750- F. Obviously, the distillation range of each individual fuel oil will cover a narrower boiling range falling, nevertheless, within the abovespecified limits. Likewise, each fuel oil will boil substantially continuously throughout its distillation range.

Particularly contemplated among the fuel oils are Nos. 1, 2 and 3 fuel oils used in heating and as diesel fuel oils, and the jet combustion fuels. The domestic fuel oils generally conform to the specifications set forth in ASTM Specifications D396-48l. Specifications for diesel fuels are defined in ASTM Specifications D975-48T. Typical jet fuels are defined in Military Specification MlL-F-5624B.

The amount of the herein-defined additives that is incorporated into the petroleum distillates in accordance with this invention will depend upon the intended purpose and the particular composition of the additive as they are not all equivalent in their activity. Thus, some may have to be used in lesser or greater concentrations than others. In many cases, in which it is desired to obtain a plurality of beneficial results in fuel oils, namely to reduce screen clogging, sedimentation and to inhibit against rusting of ferrous metal surfaces, additive concentrations varying between about 10 pounds/thousand barrels of fuel oil and about 200 pounds/thousand barrels of fuel are employed. In cases wherein it is desired not to accomplish all of such results, lower concentrations can often be used with satisfactory results. In general, however, the amount of the additive embodied herein that is added to the petroleum distillate, in order to achieve a beneficial result, will vary generally between about 0.5 pound to above 200 pounds/thousand barrels of the distillate and, preferably, between about 10 and about 200 pounds/ thousand barrels of the distillate.

if it is desired, the distillate fuel compositions can contain other additives for the purpose of achieving other results. Thus, for example, there can be present foam inhibitors, ignition and burning quality improvers, etc. Examples of such additives are silicones, dinitropropane, amyl nitrate, metal sulfonates, haloalkanes, phosphate esters, and the like.

The additives utilized for practice of this invention are methane succinamic acids from the groupconsisting of Cat- 01:

and

wherein R is an aliphatic hydrocarbon group containing between about 10 and about 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom. In practice of this invention utilizing such additives for imparting the aforesaid advantages to the distillate fuels, the presence of the tertiary group (R) substantially inhibits the distillates against objectionable emulsification, as is often encountered when use is made of corresponding compounds but in which R is a straight chain alkyl group. Thus, and although the present invention can be practiced by use of the additives embodied herein wherein R is a tertiary group, in mixture with corresponding compounds but in which the R group is a straight chain alkyl group, the concentration of the latter should be maintained at an amount less than sufficient to impart objectionable emulsification characteristics to the distillate composition.

Such additives can be prepared by heating one mole of the compound NH-R ,I NHR with one mole of the succinic anhydride at 75 -100 C.

for 1 to 5 hours to produce the additive of Formula I, in accordance with the following equation:

GH NH-R GH -(l? NI-I-R and by heating one mole of said I'm-R with 2 moles of succinic anhydride at 75-100 C. for

1 to 5 hours to produce the additive of Formula II in accordance with the following equation:

The starting methane amine reactant, i.e., of the formula I'm-R can be prepared by heating, with stirring at 95"15() C. for 1 to 3 hours, one mole of paraformaldehyde with two moles of RNH with elimination of one mole of Water, the R having the aforesaid significance of being a tertiary aliphatic hydrocarbon group containing between about and about 30 carbon atoms and a tertiary carbon atom directly attached to the nitrogen atom. Illustratively, the compound NIiIR NII-R is prepared in accordance with the following equation:

NHR

Non-limiting examples of the primary amine (RNH from which the R group of the additives embodied herein is derived, are t-dodecyl primary amine, t-tetradecyl primary amine, t-pentadecyl primary amine, t-hexadecyl primary amine, t-octadecyl primary amine, t-eicosyl primary amine, t-t'etracosyl primary amine, and t-triacontyl primary amine,- and mixtures of such amines.

In order to more fully describe the invention, the following examples are set forth for purposes of illustration and not limitation. In the examples, the primary amines, designated amine A, amine B, and amine C comprised the following:

Amine Aa mixture consisting principally of alkyl primary amines having an amino group directly attached to a tertiary carbon atom with the number of carbon atoms in the range of 12 to 15.

Amine B-similar to amine A but with the number of carbon atoms varying from 18 to 24.

Amine Ca mixture of primary aliphatic amines con taining approximately 10% hexadecylamine, 10% octadecylamine, 35% octadecenylamine and 45% octadecadienylamine.

EXAMPLE 1 A mixture of 200 gms. (1 mole) of amine A, 15 gms. (0.5 mole) of paraformaldehyde and 100 cc. of benzene was heated under reflux (95 C.) for 2 hours to form the bis (amine A) methane. The amount of water collected during the reflux was 9 cc., theory 9 cc. A quantity of 17 cc. of benzene came over with the water. To the above his (N-amine A) methane was added at room temperature with stirring 50 gms. (0.5 mole) of succinic anhydride. The mixture was heated with stirring at C. for 2 hours. The final product, the bis (N-amine A) methane succinamic acid, which contained 71 gms. of benzene was clear and fluid at room teml N.N.=Neutralization number.

EXAMPLE 2 A mixture of 200 gms. (1 mole) of amine A, 15 gms. (0.5 mole) of paraformaldehyde and 100 gms. of benzene was refluxed at C. for 2 hours to form the his (N-amine A) methane. The amount of water collected during the reflux was 9 cc., theory 9 cc. To the above bis (N-amine A) methane was added at room temperature with stirring gms. (1 mole) of succinic anhydride. The mixture was stirred at 8595 C. for 2 hours. The reaction product, the bis (N-amine A) methane bis-succinamic acid, being viscous, Was diluted with 75 gms. of benzene and filtered through Hyflo clay. The final product which contained 37% benzene was clear and fluid at room temperature.

A mixture of 300 gms. (1 mole) of amine B, 15 gms. (0.5 mole) of paraformaldehyde and 100 gms. of benzene was refluxed at 95-115 C. for about 2 hours to form the bis (N-amine B) methane. The amount of water collected during the reflux was 9 cc., theory 9 cc. A quantity of 36 gms. of benzene came over with the water. To the above his (N-amine B) methane was added at room temperature with stirring 50 gms. (0.5 mole) of succinic anhydride. The mixture was stirred at 95 C. until all the succinic anhydride was reacted (about 2 hours). The reaction product, the his (N- amine B) methane succinamic acid, was filtered through Hyflo clay. The final product which contained 16% benzene was clear and fluid at room temperature.

Analysis Estimated Found Percent N- 3. 8 3. 2 N.N 78 71 EXAMPLE 4 A mixture of 150 gms. (0.5 mole) of amine B, 7.5 gms. (0.25 mole) of paraformaldehyde and 203 gms. of xylene was refluxed at 142 C. for approximately 2 hours to form the bis (N-amine B) methane. The amount of water collected during the reflux was 4.5 cc., theory 4.5 cc. To the above his (Nsamine B) methane was added at room temperature with stirring 50 gms. (0.5 mole) of succinic anhydride. The mixture was stirred at 95 C. until all the succinic a-nhydride was reacted (3 hours). The reaction product, the bis (N-amine B) methane bi-s-succinamic acid, was filtered through I-Iyflo clay. The final product which contained 50% xylene was clear and fluid at room temperature.

EXAMPLE -5 A mixture of 150 gms. (0.75 mole) of amine A, '75 gms. (0.25 mole) of amine C, grns. (0.5 mole) of paraformaldehyde, 150 gms. of xylene and 150' cc. of benzene was refluxed at 92 C. for approximately 2 hours to form the bis (N-mixed 75 mole percent amine A-25 mole percent amine C) methane. At the end of the reflux the temperature was gradually raised to 125 C. to dist-ill out the benzene. The amount of water collected during the reflux was 9 cc., theory '9 cc. To the above bis (N-mixed 75 mole percent amine A-25 mole percent amine C) methane was added at room temperature 50 gms. (0.5 mole) of succinic anhydride. The mixture was stirred at 85 95 C. for 2 hours. The final product, the his (N-rnixed 75 mole percent amine A-25 mole percent amine C) methane succinamic acid, which contained 37% xylene was clear and fluid at room temperature.

A mixture of 100 gms. (0.5 mole) of amine A, 150 gms. (0.5 mole) of amine C, 15 gms. (0.5 mole) of paraformaldehyde, 150 gms. of xylene and 100 cc. of benzene was refluxed at 95 C. for approximately 2 hours to form the his (N-mixed 50 mole percent amine A-50 mole percent amine C) methane. At the end of the reflux the temperature was gradually raised to 125 C. to distill out the benzene. The amount of water collected during the reflux was 9 cc., theory 9 cc. To the above his (N-mixed 50 mole percent amine A-50 mole percent amine C) methane was added at room temperature 50 gins. (0.5 mole) of succinic anhydride. The mixture was stirred at 85- 95 C. for 2 hours. The final product, the his (N-mixed 50 mole percent amine A-SO mole percent amine C) methane succina-mic acid, which contained 33% xylene was clear and fluid at room temperature.

In order to illustrate the effectiveness of the additives embodied for use herein as anti-screen clogging agents for fuel oils, Table I sets forth data obtained by subjecting a fuel oil blend, as defined in Table I, to the following test along with the same blend containing the concentrations shown of the additives prepared in the foregoing examples. As shown, the use of the additives embodied by the present invention markedly reduced the screen cl gging characteristics of the fuel oil blend.

Screen clogging of fuel oils The test is conducted using a Sundstrand V or S1 home fuel oil burner pump with a self-contained -mesh Monel metal screen.About 0.05% by weight, of naturally-formed fuel oil sediment, composed of fuel oil, water, dirt, rust, and organic sludge is mixed with 10 liters :of the fuel oil and the mixture is circulated by the pump through the screen for 6 hours. The sludge deposited on the screen is washed off with n-pentane and filtered through a tared Gooch crucible. After drying, the material in the Gooch crucible is washed with a 5050 (volume) acetone-methanol mixture. The total organic .sediment is obtained by evaporating the pentane and the acetone-methanol filtrates. Drying and weighing the Gooch crucible yields the amount of inorganic sediment. The sum of the organic and inorganic deposits on the screen can be reported in milligrams recovered or converted into percent screen clogging.

TABLE I.-SCREEN CLOGGIN G TESTS [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run c0rnponent-appr0xima.tely 320-6401. boiling range] The data set forth in the following Table II illustrates the highly effective inhibition against sedimentation that results by use of the additives embodied herein in fuel :oils when subjected to storage at F. for 12 weeks.

TABLE 11 [Inhibitors blended in a fuel oil blend comprising 60% catalytically cracked component and 40% straight run component-approximately 320-640 1*. boiling range] Inhibitor Concn.. lbs./ Sediment,

1,000 bbls. mg./liter Uninhibited fuel blend O 27 Uninhibited fuel blend-l-Ex. 1 25 4 Uninhibited fuel blend v 0 27 Uninhiblted fuel blend-l-Ex. 2. 10 7 Uninhibited fuel blend 0 27 Uninhibited fuel blend+Ex 3 50 2 Uninhibited fuel blend 0 27 Uninhibited fuel blend+ 50 5 Uninlribited fuel blend. 0 36 Uninhioited fuel blend-l-Ex. 5- 10 5 Uninbibited fuel blend 0 36 Uninhibited fuel blend+Ex. 6 50 5 Over and above the improvements that result, with respect to anti-screen clogging and anti-sedimentation, by use of the herein-defined additives in fuels, such additives also effectively inhibit fuel oils against rusting of ferrous metal. In illustration, and under the test conditions of ASTM Rust Test D-665, a fuel oil blend (60% catalytically cracked component, 40% straight run componentapproximately 320-640 F. boiling range) failed to pass such a test but, when concentrations of 10 parts/million of the additive of Ex. 1, or 5 parts/million of the additive of Ex. 2, or 10 parts/million of the additive of Ex. 5, or 5 parts/million of additive of Ex. 6 were added to the fuel '3" oil blend, the resulting additive-containing blends passed the stated rust test.

In order to illustrate the importance of the presence of a tertiary carbon atom in the group represented by R in the aforesaid Formula I, an addition agent as embodied herein having such a t-carbon atom (derived from the t-alkyl amine hereinbefore designated amine A) was subjected to the following fuel oil emulsion test along with a corresponding methane succinamic acid but in which the R was derived from the n-aliphatic amine designated hereinbefore as amine C. The additives were used in the concentrations set forth in Table III in a hydrofined fuel oil.

Fuel oil emulsion test A 200 milliliter portion of the fuel to be tested and 20 milliliters of distilled water are placed in a clear glass pint bottle. The bottle is tightly capped and set in an Ever'back mechanical shaker in a horizontal position such that the maximum degree of agitation is afforded. The shaker is run at its maximum setting for minutes. The bottle is then removed and allowed to stand in an upright position in the dark for 24 hours. At the end of the 24 hour settling period, the appearance of the water layer is noted. The fuel layer is siphoned off, care being taken not to disturb the oil-water interface, and is discarded. A fresh portion of the fuel oil being tested is then added, and the described sequence of steps is repeated up to ten times. This test procedure has been found to provideemulsions in inhibited oils similar to emulsions which occur in the oils after prolonged periods of normal handling and storage in the field on a commercial basis.

On the basis of the rating scale set forth hereinafter for reporting results from such an emulsion test, a fuel is considered to have emulsion-forming tendencies if, after any 24 hour settling period, a rating of three or greater is obtained; and a rating of five or greater on any contact constitutes a test failure.

Rating scale for reporting emulsion test results Description of emulsion Clean break on the interface of oil and water. No dirt,

skin, or bubbles present.

1 Very slight skin at the oil-water interface that usually does not break on tilting the bottle.

Skin at oil-water interface, heavier than #1 and usually aceompained with dirt and bubbles on the skin. No evidence of any white emulsion.

First sign of white emulsion. Usually forms at the bottom and in the center of the bottle. It is circular in shape and approximately M to 1 inch in diameter.

Approximately the same amount of emulsion on the bottom of the bottle as #3. However, emulsion is also beginning to form at oil-water interface and extends A2 to M0 downward into the water layer. Roughly of water layer occupied by emulsion.

Circular emulsion at bottom of bottle extends outward and upward resembling spokes. Emulsion at the interface a little thicker than #4.

6 More emulsion than #5. Thin film of emulsion forming on sides of bottle surrounding the water layer. Water is still visible looking through the sides and looking up from the bottom of the bottle.

7 Emulsion on bottom of water layer is almost solid.

Emulsion on sides of bottle is broken in a few spots enabling the operator to see the water layer.

8 Semi-solid emulsion with perforations or bubbles similar to a honeycomb. No water visible except that seen in the bubbles.

9 Same emulsion as #8 but with less bubbles. 75-90% emulsion is solid.

10 Almost completely solid emulsion with only a few air bubbles visible.

11 Completely solid emulsion (mayonnaise type).

TABLE IIL-EMULSION TEST As is apparent from the data in Table III, the methane suecinamic acid containing the tertiary carbon atom did not impart any emulsifying characteristics to the fuel oil but, when the same fuel oil contained the methane succinamic acid with the n aliphatic group, the resulting composition emulsified severely, as per the designated rating of 11, under the conditions of the aforesaid emulsion test.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

ll. A non-lubricating normally liquid petroleum distillate containing a small amount, based on the weight of the distillate and suflicient to inhibit said distillate against screen clogging, of a succinamic acid selected from the group consisting of and wherein R is a tertiary aliphatic hydrocarbon group containing from about 10 to about 30 carbon atoms and having a tertiary carbon atom attached directly to the nitrogen atom.

2. A composition as defined in claim 1, wherein the petroleum distillate is a hydrocarbon distillate fraction having an initial boiling point of at least about F. and an end boiling point not higher than about 750 F.

3. A composition, as defined in claim 1, in which the succinamic acid is present in an amount of from about 0.5 to about 200 pounds per thousand barrels of the petroleum distillate.

4. A composition, as defined in claim 1, wherein the petroleum distillate is a hydrocarbon distillate fraction having an initial boiling point of at least 75 F. and an end boiling point not higher than about 750 F. and R in the succinamic acid contains from about 12 to about 15 carbon atoms. v

5. A composition, as defined in claim 1, wherein R in the suecinamic acid contains from about 18 to about 24 carbon atoms.

References Cited by the Examiner UNITED STATES PATENTS 2,598,213 5/52 Blair 252392 2,604,451 7/52 Rocchini 25251.5 2,699,427 1/55 Smith et a1 252-390 2,908,711 10/59 Halter et a1. 252-392 3,035,907 5/62 Halter et a1. 44-71 DANIEL E. WYMAN, Primary Examiner. 

1. A NON-LUBRICATING NORMALLY LIQUID PETROLEUM DISTILLATE CONTAINING A SMALL AMOUNT, BASED ON THE WEIGHT OF THE DISTILLATE AND SUFFICIENT TO INHIBIT SAID DISTILLATE AGAINST SCREEN CLOGGING, OF A SUCCINAMIC ACID SELECTED FROM THE GROUP CONSISTING OF 